Endoluminal prosthesis, i.e. stents, particularly of the self-expanding type, are known for example by U.S. Pat. No. 4,665,771, U.S. Pat. No. 4,665,905, U.S. Pat. No. 4,925,445 or EP-A-0928606.
These endoluminal prosthesis, though being acceptable in many respects, particularly for their great flexibility and resilience, which enable them to be easily positioned in narrow and tortuous passages in their collapsed state, in some cases they are not sufficiently suitable, when expanded, to support the vessel walls, in order to maintain a proper free lumen for blood to pass therethrough.
Furthermore, in some cases the complex geometry of such known stents may be harmful, since it can hang up to or pinch the vessel wall, thus favouring the re-forming of obstructions, such as plaques and stenosis.